Scooter Braun, the pop star's manager, said that Bieber had been admitted to a London hospital on Thursday night as a precautionary measure after feeling tired and nauseous during a concert at the O2 Arena.

Bieber, who is thought to be less than 12 weeks pregnant confirmed the news to his fans in a Tweet on Friday morning.

"He's been released from the hospital early this a.m. after a treatment for acute morning sickness and while he's feeling a little under the weather, he's planning on going ahead with tonight's show," his manager said later in the day.

News of his pregnancy goes some way to explaining his erratic behavior over recent weeks, including arriving two hours late for a concert, multiple emotional outbursts on Twitter and vomiting on at least two occasions while clubbing.

Reactions from fans have been mixed, with some expressing their support for the star and others criticizing him for continuing his exhausting concert schedule while pregnant.

Bieber told reporters after his concert on Friday night that doctors had advised him to perform either sitting down or standing still, and to quit smoking and binge drinking.

When asked when he had found out about the pregnancy he simply replied "recently", and then added "I didn't believe it myself until the ultrasound. Then I saw her face, and now I'm a belieber... believe... er, never mind"

"Baby x3 oh. Thanks for your support. Babs and i think ur the best fans eva" - Pregnant Bieber tweets a picture from his hospital bed.

Yeah I was thinking about that too, but then I thought it might be more fun if readers didn't get the joke until the first (or third/fourth) paragraph.

I welcome any suggestions though. I wrote it in one go with no real plan other than combining recent Bieber news with a celebrity pregnancy report. He's always the butt of gender jokes but I wanted to do a different take on that.

I did laugh when I read it back to myself. I hope at least one of you guys did too

That's what I was aiming for, but I also wanted to subtly reference him being the pregnant one in the headline without making it too obvious. In the absence of any better ideas I just settled for "parenthood"